In my system I have windows on one of my hard driver and I have installed Xen cloud platform on the other one. The installation is complete now but I don't know how can I load Xen after reboot? In boot menu I don't have option to choose which hard drive I should load! Can anyone help me?
I'm not a guru and I haven't yet tried this(I’m hoping to test a similar setup soon), but I’ll try give you some direction...
This guy does dual boot for two windows versions on two drives, but I think a similar process can be used for your case:
http://atagunov.blogspot.hk/2012/04/installing-grub2-without-linux.html
basically, what you have to do is run gparted to create a small 128MB partition to the beginning of one of the drives so that you can install grub2 bootloader to that partition.
configure grub2 to list xen and windows as options, create the grub.cfg file with the 'make-config' script provided by grub2.
Lastly, press f2 at boot to get into teh bios abd change the boot device order so that the first choice is the one with grub2 installed on it.